1. Field of the Invention
This invention relates generally to the art of thin film device processing and fabrication. More specifically, the invention relates to the structure of Organic Light Emitting Diode devices and displays.
2. Related Art
Conjugated polymers and small-molecules are of increasing interest as new materials for organic light electronic devices. Conventional devices based on polymer used solution processing techniques and small molecules devices thermal evaporation techniques. The simplest solution processed polymer based OLED incorporates an active region with a light emitting polymer and/or small molecules blended into a solution that is coated onto the transparent anode by spin-casting or printing methods. In several cases a hole transporting interlayer is included between the anode/anode buffer layer and the active region in order to improve hole injection and transport. In contrast, small molecule devices typically consist of several stacked organic layers, each one optimized to perform a particular function. In polymer OLEDs, it is difficult to adjust the color and light output.